We’re not sure why he did this, but we’re guessing Bieber fans went into lustful hysterics at the sight of his bare bottom. Others may have experienced the “horrible car accident” effect: Can’t look away…

The Biebs bared his bum and then promptly posted the photo to Instagram. He then did the old quick deletion — but as we all know, whatever exists electronically will exist for always. The photo got over 15,000 likes and received about 3,000 comments.